Extension-boom.



N. E. ANDERSEN.

EXTENSION BOOM.

APPLICATION FILED JULY 28.1915.

Patented D00. 7, 1915.

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EXTENSION BOOM.

APPLICATION FILED JULY 28,1915.

1,163,497. Patented Dec. 7, 1915.

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NILS ENGI-IOLM ANDERSEN, OF MIAMI, FLORIDA.

EXTENSION-BOOM.

Specification of Letters Patent.

Patented Dec. 7, 15915.

' Application filed July 28, 1915. Serial No. 42,241.

To all whom it may concern Be it known that I, NILs E. ANnnRsnN, a

subject of the King of Norway, and a resident of Miami, in the county of Dade and State of Florida, having declared my intention and petitioned to become a citizen. of the United States, have invented a new and Improved Extension-Boom, of which the following is a full, clear, and exact description. I

My invention, While applicable to booms generally, is more particularly intended for use on'derricks of the mast and boom type, and is especially'useful in building construction. I i

lVith derricks having ordinary booms and employed on the floor of a building, the sweep of the boom coy ers a comparatively small area, particularly since the derrick is employed to hoist the material from the street and deposit it on the floor to which it has been raised. The limited area of operations of the ordinary derrick requires great expenditure of time and labor in distributing the material after it is hoistedand deposited on the floor, since steel beams are required to be bulled, as itis termed, by manual labor. Moreover, an auxiliaryportable derrick is required to set the steel ele ments.

The invention hasfor its object to provide an extension boom which, when'applied to a derrick of the character referred to, employed in building operations, will have a materially increased area of operation whereby to avoid the major portion of the manual labor now necessary. I

A further object of the invention is to provide an extension boom which'will be un-, failing in its operation and reliable as to strength and etliciency.

In carrying out my invention, the extenion boom is mounted one main boom which is pivotally mounted on the foot casting of the mast, and an extension fall rigging is provided controlled by an engine drum, to gether with safety devices in the way of improved guiding means for the extension boom, locking devices to hold the extension boom in the adjusted position, and a support for the extension boom when withdrawn entirely from the extended position. y

The invention will be particularly explained in the particular description following Reference is had to the accompanying due rubbing and wear'of drawings forming part of this specification, in which'similar characters of referencev indicate corresponding parts in all the views, and in which Figure l is a diagrammatic view showing an elevation of a derrick having my improved extension boom; Fig. 2 is a fragmentary longitudinal vertical section of parts of the main and auxiliary boom, together with looking and guiding elements; Fig. 3 is'a sideieleva tion showing the main and extension booms folded'against the mast; Fig. 4c is a cross-section on the line l4Iig. 3; and Fig. 5 "is. a cross-section on the line 55 Fig. 3.

In carrying out my invention in accord I ance with the illustrated example, a mast 10 is mounted to turn on a suitable base 11. The foot casting 12 of the mast has pivoted thereto at 13 the foot casting let of a main boom 15 whereby the said boom may fold toward or from the mast 10.

A topping lift is provided to control both the booms from a single drum, the rope or cable having such a running connection with the booms as to equalize and roperly distribute the strain. The rope 1 ping lift extends upwardly fromthe drum (not shown) over a guide sheave 1 7 at the top of the mast 10, and is rove as follows: fromsheave 17 through a block 17 on the outer end of the main boom 15, thence back through a standing block 17 at the mast head, thence outward and through a block 18 on the outer end of the auxiliary boom 16, thence back through a standing block 1'8 at the mast head, and then outward again to the block 18 to which the end of the cable is made fast. The block 18 is connected with the auxiliary boom 16 by a short length of chain 18 wherebyto position the said block 18 at the proper angle when the auxiliary boom is retracted, and thereby prevent unthe cable.

A hoisting fall designated generally by the numeral 19 is employed, the rigging including a fall block 19 together with a standing block l9 carried by the outer end of the extension boom.

In order toadjust the position of the extension boom 16, an extension fall designated generally by the numeral 20 is em ployed and actuated by a suitable drum (not shown). The rigging of the topping lift elem ents, h'oisting fall, and extension fall, involve only an engine with two drums, one

of the, tops the latter,

. adjacent to the path gine belng used for the extension fall 20.

The extension and hoisting falls both come I through the foot of the mast and its casing 12 to the engine (not shown).

The cableof the extension fall 20 runs from its drum over pulleys 21, 22, on the main boom at an intermediate point on and over a pulley 23 on the extension mast at the inner end thereof, the end of the rope being made fast as at to the extension mast; The pulleys 2-1, 22, are mounted on a fitting boom 15, said fitting including a band 2d which embraces the extension mast 16 to restrain and guide the same. 'Similarly, a.

fitting 25 is secured to the main'boom 15 at the outer end and includes a band 25 guidingly embracing the boom 16.

In order to afford wear surfaces on the extension boom 16 in its movements through the elements 24, .25, the extension boom is formed with longitudinally ranging members 26 preferably in the form of half round rods or bars, which serve also to give free movement to the Y extension boom. The proper movement of the extension boom'is further insured by an interlocking sliding engagement between the inner end thereof and the main boom, for which purpose a longitudinal rib or bar 27 is fixedly secured to the main boom 15 along the face thereof of travel of the exten-' sion boom, said head being undercut in the form of a T-head, as clearly shown in Fig. 41.

-A co-acting guide member 28 is secured or formed upon the cap or ring 29 on the inner end of the extension boom, and presents a longitudinal slot which is undercut to cor- T-head 27, slidingly re-= respond with the ceiving the latter. Near the outer end the extension boom 16 may have a wear band 30.

In order to hold the extension boom in the adjusted position, extended to a greater or less extent, co-acting stop members are provided on the main and extension booms These comprise a pawl 31 on the main boom and, stop shoulders on the extension boom.

Said stop shoulders are provided in the present example by a longitudinal rib 01- bar 32 on the outer end of the extension boom anda stop block 33 near the innerend.

of the saidboom. The pawl 31 is mounted on a rock shaft- M having bearings in the fitting 24: said shaft havinga lateral arm 35 whi ch'is connected to a cord or rope 36, .WlllCll 1n practice extends to any convenient point adjacent to the drums controlling the derrick. Thepawl 31 is under the influence of a compression spring 37 :which in the present example is coiled about a pin 38 (Fig. 2) which enters a recess inthe main boom 15.

It is to be understood that the minor de- 21 secured to the main in the same, whereby the extension boom.

will be forced outwardly. If the extension boom is desired to be only partially extended,it may beheld by the pawl 31 engaging the stop 32,.or when completely extended it will be held by the pawl engaging the stop 33, so that retrograde movement of the extended boom will be prevented. It is to be understood that these stops may be applied.

at any desired points along the extension boom. When it is desired towithdraw the extension boom, an outward'movement is given to the same sufficient to release the engagement between the pawl 31 and the adjacent stop shoulder, and a pull on the rope or cord 36 will displace the pawl from the path of the shoulder. The extension fall rope 20 is then slackened, permitting the extension beam to slide downwardly until it comes to a rest on the seat l the topping lift .17

as the extension boom slides inwardly. When the topping lift is manipulated to swing the booms against the mast as indicated in dotted lines'in Fig. 1, and in full lines Fig. 3, it will be seen that the weightof the ex tension mast is taken up, by the. seat 14 so that the guide fittings are relieved of strain. By the described construction also it will be apparent that the extension boom may be made to cover a great area and at the same time it may be collapsed sufiiciently to clear guy ropes (not shown) with which the mast 10 isnecessarily equipped in practice.

. Having thus described my invention, what I claim as new and desire to'secure by Letters Patent, is: I .1 1. A boom comprising a main boom, a fitting on the same at the foothaving means to pivotally secure the boom to a support,

, being in the meantime gradually taken up and presenting a seat at a side thereof, an

extension boom slidable on the main boom to or from said seat,means to slide said exten- S1011 boom outwardly a topping lift common to both booms, a fittingon thesa'id boom near its outer end, said fitting embracing the extension boom, a fitting on the main boom inward from the outer end having a band embracingthe extension boom, the said extension boom having a series of longinal rib on one of'said booms near the inner end presenting an undercut head disposed "tudinal guide members thereon, a longitudithe said other boom presenting an undercut slot receiving the said head, thereby insuring a sliding inter-engagement between the two booms, co-acting stop means on the respective booms to hold the extension boom at different degrees of extension, and to prevent retrograde movement thereof, and means to swing the two booms on the pivotal connection of the foot of the main boom.

2. In a derrick, a mast, a main boom, an auxiliary boom slidable on the main boom to an extended or a retracted position, and a topping lift common to both booms and having a connection with each of said booms.

3. In a derrick, a mast a boom, an auxiliary boom slidable on the main boom to an extended or a retracted position, and a topping lift for the booms, including a cable having running engagement with each boom.

4. In a derrick, a mast, a main boom, an auxiliary boom slidable on the main boom to an extended or a retracted position, and a topping lift including a cable running from the mast head, a block on the main boom through which the cable is rove, a standing block at the mast head through which the cable is rove from the main boom, a block on the auxiliary boom through which the cable is rove from said standing block, and a second standing block at the mast head through which the cable is rove from the block on the auxiliary boom, the end of the cable being returned and made fast to said block on the auxiliary boom.

5. A boom comprising a main boom, a fitting thereon at the foot having means to pivotally secure the boo-m to a support, said fitting presenting a lateral seat, and an extension boom slidable on the main boom to and from said seat.

6. A boom comprising a main boom, means to pivotally mount the same, an extension boom slidable on the main boom, and means establishing guided engagement sion boom vand the main boom, said means including a longitudinal rib on one boom terminating in an undercut headdisposed in the direction of the boom and a corresponding guide member on said other boom embracing the said head and slidable thereon along the said rib.

7. A boom comprising a main boom, means to pivotally mount the same on a support, an extension boom slidable relatively to the main boom, and a fitting on the main boom presenting a member snugly embracing the extension boom, the said extension boom having a series of guide members ranging longitudinally thereof and slidably encircled by said guide member.

8. A boom comprising a main boom, means to pivotally mount said boom on a support, an extension boom slidable on the main boom, actuating means to move said extension boom outwardly, a fitting on the main boom including a member embracing the extension boom and guiding the same, and co-acting stop means to hold the extension boom at different degrees of extension and prevent retrograde movement thereof, said stop means comprising a plurality of members presenting rearwardly facing stop shoulders on the extension boom, a pawl on the main boom normally disposed in the path of movement of said members and receiving the weight of the extension boom, and means to rock said pawl out of the path of said members when relieved of the weight of the extension boom by the said actuating means. a

In testimony whereof I have subscribed my name to this specification in the presence of two subscribing witnesses.

NILS ENGHOLM ANDERSEN.

Witnesses:

INIELS P. NIELSEN, S. B. GEDNEY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

